“So” you might ask. What’s the best way to go fast? What’s gonna give me the most bang for my buck? What’s the most effective way to make major horsepower?
The answers depend largely on who is being asked. But dollar for dollar, few upgrades can match the economical performance of forced induction. Whether making use of turbochargers or superchargers (there IS a difference) few things can add power as effectively as a forced induction style engine setup. No matter which one you choose, the basic idea is the same.
An engine burns fuel, mixed with a precise amount of air to run properly. To increase power output, the primary goal is to get the engine to burn more fuel in less time. Forced induction systems mechanically pump excess air into the engine to increase the amount of gasoline that can be burned with each piston stroke.
Turbochargers are the most common application of the forced induction concept. They utilize spent exhaust gasses to power a turbine which then forces clean, unburned air into the engine. Turbos tend to be very efficient. During normal driving they don’t really do anything at all.
But when you step on the gas they start to work. This can allow a very fast car to also return impressive mpg numbers. However the main drawback is that it takes time for them to spool up. In most turbocharged vehicles there will be a perceptible delay between when you press on the accelerator and when full horsepower is produced. This can be particularly problematic when driving at low speeds. Near idle, your turbo may do absolutely nothing at all!
Another form of forced induction is supercharging.
This system is quite similar to turbocharging. It does make use of a turbine to coerce the atmosphere into your motor. The main difference is that the turbine is driven by the crankshaft with the use of a heavy duty belt. Not much different from a serpentine belt, it connects to a crank pulley and subsequently to a supercharger pulley with various idlers and tensioners in between.
The biggest advantage is that the turbine never stops spinning, even at idle. It’s always directly connected to the crankshaft. There’s no delay, or “turbo lag” between when you step on the gas and when full power is produced. But the tradeoff is that superchargers, as a general rule, are less efficient, and don’t make quite as much power as turbochargers at high engine speeds.
Don’t get me wrong, forced induction isn’t that elusive perfect upgrade. It brings to light a whole new set of problems. What happens when your engine makes too much power? You can always crank up the boost pressure but making upgrades to handle the excess load is going to be your biggest priority.
For example, consider an elevator rated for 2000 lbs. If you load it up with ten tons of lead it’s cables are going to snap and send it plummeting toward the Earth! It’s the same idea with your motor. The stock insides can only handle so much power before they break. Beefing up the internals is imperative to building a reliable forced induction engine.
These setups do seem very expensive on the surface. The cost of turbochargers, superchargers, engine tuning, and various miscellaneous components can quickly become a considerable financial burden. But with your investment you stand to gain more horsepower per dollar than you could ever imagine.
Plus the systems are capable of growing with the rest of your upgrades. So you threw some aftermarket pistons in that motor? Go ahead and crank up the boost! Once you experience the viscous acceleration of a forced induction style engine setup, trust me, you’ll never go back again.